Photoelectron Photoion Coincidence Spectroscopy of NCl₃ and NCl₂

Abstract

We investigate NCl3 and the NCl2 radical by photoelectron‐photoion coincidence spectroscopy using synchrotron radiation. The mass selected threshold photoelectron spectrum (ms‐TPES) of NCl3 is broad and unstructured due to the large geometry change. An ionization energy of 9.7±0.1 eV is estimated from the spectrum and supported by computations. NCl2 is generated by photolysis at 213 nm from NCl3 and its ms‐TPES shows an extended vibrational progression with a 90 meV spacing that is assigned to the symmetric N−Cl stretching mode in the cation. An adiabatic ionization energy of 9.94 ± 0.02 eV is determined.